Abstract:

All India tuna production continued to increase with fluctuations from 848 t in 1951 to 64,006 t in 2006, with a peak production of 64,006 t in 2006. During 1985-2006 it varied from 27,148 t in 1985 to 64,006 t in 2006 with annual average landings of 39,937 t. Annual average tuna production by different maritime states was 17,041 t (42.7%) by Kerala, 5,615 t (14.1%) by Gujarat, 5,000 t (12.5%) by Tamilnadu, 2,741 t (6.9%) by Lakshadweep, 2,812 (7.0%) Karnataka, 2,716 t (6.8%) by Maharashtra, 2,009 t (5.9%) by Andhrapradesh, 1,095 t (2.7%) by Goa, 444 t (1.1%) by Andaman & Nicobar Islands, 262 t (0.7%) by Pondicherry, 134 t (0.3%) by Orissa, 68 t (0.2%) by West Bengal. Tamilnadu catch varied from 1,336 t in 1985 to 10,912 t in 2006 with an average of 5,000 t forming 1.4% of total marine fish production during 1985-2006. Species composition of all India tuna catch was Euthynnus affinis (51.2%), Katsuwonus pelamis (4.1%), Thunnus tonggol (10.4%), Auxis spp. (20.7%) and other tunnies (13.6%) and the species composition of Tamilnadu was E. affinis (59.7%), K. pelamis (11.5), Auxis spp. (12.5%), T. tonggol (5.5%) and other tunas (10.8%).

Tuna landings at Chennai Fisheries Harbour varied from 150 t in 2001 to 1005 t in 2003 with an average annual production of 595 t during 1999-2006. The annual average catch rate increased from 131.7 kg/unit in 1999 to 730.0kg/unit in 2006 and the overall average catch rate was 400.9 kg/unit during 1999-2006. The species composition of tuna at Chennai Fisheries Harbour was E. affinis 25.2% followed by K. pelamis 35.8%, T. albacares 22.3, A. thazard 16.3% and T. tonggol 0.3%. The growth parameters and mortality rates of Euthynnus affinis are estimated to be L∞75 cm, K 1.42/yr, M 1.77, Z 4.86, F 3.09 and exploitation rate U 0.631, that of K. pelamis are L∞ 79 cm, K 1.65/yr, M 1.92, Z 4.7, F 2.78, and U 0.587 and that of T. albacares are L μ 149.6 cm, K 0.75/yr, M 0.96, Z 2.37, F 1.41, and U 0.539. All the three species presently studied are exposed to marginally higher fishing pressure by the mechanized drift gillnets of Chennai coast. Based on the all India production the standing stock of E. affinis is estimated to be 6618 t and average annual stock is 32409 t.

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Date 2009/04/15

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